record_manager.h

 
/* Copyright (c) 2021 Xie Meiyi(xiemeiyi@hust.edu.cn) and OceanBase and/or its affiliates. All rights reserved.
miniob is licensed under Mulan PSL v2.
You can use this software according to the terms and conditions of the Mulan PSL v2.
You may obtain a copy of Mulan PSL v2 at:
         http://license.coscl.org.cn/MulanPSL2
THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
See the Mulan PSL v2 for more details. */
 
//
// Created by Meiyi & Longda on 2021/4/13.
//
#pragma once
 
#include "common/lang/bitmap.h"
#include "common/lang/sstream.h"
#include "storage/buffer/disk_buffer_pool.h"
#include "storage/common/chunk.h"
#include "storage/record/record.h"
#include "storage/record/record_log.h"
#include "common/types.h"
 
class LogHandler;
class ConditionFilter;
class RecordPageHandler;
class LogHandler;
class Trx;
class Table;
 
struct PageHeader
{
  int32_t record_num;        
  int32_t column_num;        
  int32_t record_real_size;  
  int32_t record_size;       
  int32_t record_capacity;   
  int32_t col_idx_offset;    
  int32_t data_offset;       
 
  string to_string() const;
};
 
class RecordPageIterator
{
public:
  RecordPageIterator();
  ~RecordPageIterator();
 
  void init(RecordPageHandler *record_page_handler, SlotNum start_slot_num = 0);
 
  bool has_next();
 
  RC next(Record &record);
 
  bool is_valid() const { return record_page_handler_ != nullptr; }
 
private:
  RecordPageHandler *record_page_handler_ = nullptr;
  PageNum            page_num_            = BP_INVALID_PAGE_NUM;
  common::Bitmap     bitmap_;             
  SlotNum            next_slot_num_ = 0;  
};
 
class RecordPageHandler
{
public:
  RecordPageHandler(StorageFormat storage_format) : storage_format_(storage_format) {}
  virtual ~RecordPageHandler();
  static RecordPageHandler *create(StorageFormat format);
 
  RC init(DiskBufferPool &buffer_pool, LogHandler &log_handler, PageNum page_num, ReadWriteMode mode);
 
  RC recover_init(DiskBufferPool &buffer_pool, PageNum page_num);
 
  RC init_empty_page(
      DiskBufferPool &buffer_pool, LogHandler &log_handler, PageNum page_num, int record_size, TableMeta *table_meta);
 
  RC init_empty_page(DiskBufferPool &buffer_pool, LogHandler &log_handler, PageNum page_num, int record_size,
      int col_num, const char *col_idx_data);
 
  RC cleanup();
 
  virtual RC insert_record(const char *data, RID *rid) { return RC::UNIMPLEMENTED; }
 
  virtual RC recover_insert_record(const char *data, const RID &rid) { return RC::UNIMPLEMENTED; }
 
  virtual RC delete_record(const RID *rid) { return RC::UNIMPLEMENTED; }
 
  virtual RC update_record(const RID &rid, const char *data) { return RC::UNIMPLEMENTED; }
 
  virtual RC get_record(const RID &rid, Record &record) { return RC::UNIMPLEMENTED; }
 
  virtual RC get_chunk(Chunk &chunk) { return RC::UNIMPLEMENTED; }
 
  PageNum get_page_num() const;
 
  bool is_full() const;
 
protected:
  void fix_record_capacity()
  {
    int32_t last_record_offset = page_header_->data_offset + page_header_->record_capacity * page_header_->record_size;
    while (last_record_offset > BP_PAGE_DATA_SIZE) {
      page_header_->record_capacity -= 1;
      last_record_offset -= page_header_->record_size;
    }
  }
 
  char *get_record_data(SlotNum slot_num)
  {
    return frame_->data() + page_header_->data_offset + (page_header_->record_size * slot_num);
  }
 
protected:
  DiskBufferPool  *disk_buffer_pool_ = nullptr;  
  RecordLogHandler log_handler_;                 
  Frame *frame_ = nullptr;  
  ReadWriteMode rw_mode_     = ReadWriteMode::READ_WRITE;  
  PageHeader   *page_header_ = nullptr;                    
  char         *bitmap_      = nullptr;  
  StorageFormat storage_format_;
 
protected:
  friend class RecordPageIterator;
};
 
class RowRecordPageHandler : public RecordPageHandler
{
public:
  RowRecordPageHandler() : RecordPageHandler(StorageFormat::ROW_FORMAT) {}
 
  virtual RC insert_record(const char *data, RID *rid) override;
 
  virtual RC recover_insert_record(const char *data, const RID &rid) override;
 
  virtual RC delete_record(const RID *rid) override;
 
  virtual RC update_record(const RID &rid, const char *data) override;
 
  virtual RC get_record(const RID &rid, Record &record) override;
};
 
class PaxRecordPageHandler : public RecordPageHandler
{
public:
  PaxRecordPageHandler() : RecordPageHandler(StorageFormat::PAX_FORMAT) {}
 
  virtual RC insert_record(const char *data, RID *rid) override;
 
  virtual RC delete_record(const RID *rid) override;
 
  virtual RC get_record(const RID &rid, Record &record) override;
 
  virtual RC get_chunk(Chunk &chunk) override;
 
private:
  // get the field data by `slot_num` and `column id`
  char *get_field_data(SlotNum slot_num, int col_id);
 
  // get the field length by `column id`, all columns are fixed length.
  int get_field_len(int col_id);
};
class RecordFileHandler
{
public:
  RecordFileHandler(StorageFormat storage_format) : storage_format_(storage_format){};
  ~RecordFileHandler();
 
  RC init(DiskBufferPool &buffer_pool, LogHandler &log_handler, TableMeta *table_meta);
 
  void close();
 
  RC delete_record(const RID *rid);
 
  RC insert_record(const char *data, int record_size, RID *rid);
 
  RC recover_insert_record(const char *data, int record_size, const RID &rid);
 
  RC get_record(const RID &rid, Record &record);
 
  RC visit_record(const RID &rid, function<bool(Record &)> updater);
 
private:
  RC init_free_pages();
 
private:
  DiskBufferPool        *disk_buffer_pool_ = nullptr;
  LogHandler            *log_handler_      = nullptr;  
  unordered_set<PageNum> free_pages_;                  
  common::Mutex          lock_;  
  StorageFormat          storage_format_;
  TableMeta             *table_meta_;
};
 
class ChunkFileScanner
{
public:
  ChunkFileScanner() = default;
  ~ChunkFileScanner();
 
  // TODO: not support filter and transaction
  RC open_scan_chunk(Table *table, DiskBufferPool &buffer_pool, LogHandler &log_handler, ReadWriteMode mode);
 
  RC close_scan();
 
  RC next_chunk(Chunk &chunk);
 
private:
  Table *table_ = nullptr;  
 
  DiskBufferPool *disk_buffer_pool_ = nullptr;  
  LogHandler     *log_handler_      = nullptr;
  ReadWriteMode   rw_mode_ = ReadWriteMode::READ_WRITE;  
 
  BufferPoolIterator bp_iterator_;                    
  RecordPageHandler *record_page_handler_ = nullptr;  
};